Method for minimizing variation in etch rate of semiconductor wafer caused by variation in mask pattern density

Abstract

In a method for minimizing a variation in an etch rate of a semiconductor wafer caused by a variation in a mask pattern density, the method includes determining a reference amount of an etch gas for a reference mask pattern density, obtaining an optimized amount of the etch gas for a mask pattern density different from the reference mask pattern density, wherein the optimized amount is obtained by the following equation: ( the ⁢ ⁢ reference ⁢ ⁢ amount ⁢ ⁢ for ⁢ ⁢ the ⁢ ⁢ reference ⁢ ⁢ mask ⁢ ⁢ pattern density ) × ( 1 - the ⁢ ⁢ mask ⁢ ⁢ pattern ⁢ ⁢ density ) ( 1 - the ⁢ ⁢ reference ⁢ ⁢ mask ⁢ ⁢ pattern ⁢ ⁢ density ) , and the mask pattern density is a value of dividing a mask pattern area by an overall semiconductor wafer area, and applying the optimized amount of the etch gas in an etching process of the semiconductor wafer.

Dependencies are inferred from the claim text.